Primary electrolytic cell or group of cells



July 28, 1953 c. 'A. DYER 2,647, 5

PRIMARY ELECTROLYTIC CELL 0R GROUP OF CELLS Filed July 29, 1949 2 Sheets-Sheet 1 INVENTOR. CLARENCE A. DYER ATTORNEY.

July 28, 1953 c. A. DYER PRIMARY ELECTROLYTIC-CELL 0R emu? -0F CELLS 2 Sheets-Shet 2 Filed July 29, 1949 Hg SO I80 Mercury INVENTOR. CLARENCE A. DYER BY fl ATTORNEY.

patented July 28, 19K;

UNITED STATES PATENT OFFICE PRIMARY ELECTROLYTIC CELL OR GROUP OF CELLS Application July 29, 1949, Serial No. 107,556

2 Claims.

Modern technology demands ever increasing accuracy. To meet these demands, more exact reference standards are required. One such reference standard is the primary electrolytic cell of the Weston type which is used to provide a voltage standard for potentiometric work. Such cells have a certain degree of temperature sensitivity.

One object of this invention is to provide a group or plurality of such cells the different poles of which are located as close together as possible so as to be at substantially the same temperature. Such close physical spacing of the poles or of the cells themselves provides good thermal stability.

A further object of this invention is to provide a group or battery of standard cells in which the different pole portions are enclosed within a metal cover which tends to equalize the temperature at each pole portion.

Yet another object of this invention is to provide a standard cell having a casing which can be economically and eiiiciently manufactured of plastic material combining high resistance to deterioration due to electrical or chemical causes.

The various features of novelty which characterize this invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects obtained with its use, reference should be had to the accompanying drawings and descriptive matter in which is illustrated and described a preferred embodiment of the invention.

In the drawings:

Each of'the figures is a cross section on the line indicated as viewed in the direction of the arrows.

Fig. 1 is a vertical cross section on line I-I of Fig. 2 showing a single cell.

Fig. 2 is a horizontal cross section on line 2-2 of Fig. 1.

Fig. 3 is a vertical cross section on line 3-3 of Fig. 4 showing a group of cells.

Fig. 4 is a horizontal cross section on line I-4 of Fig. 3.

Figs. 1 and 2 show a standard cell having a case or container formed of a suitable plastic such as polystyrene, polyethylene or polytetrafiuoroethylene. This casing or container consists of a backing or upper plate 5 having a notch or opening 6 in its upper end. Projecting forwardly from backing 5 is a substantially cylindrical, hollow portion I in which is a cavity 8 closed at its upper end by an integrally united cap 9.

Cavity 8 has projecting from the lower portion thereof two smaller recesses, generally indicated at In and II. A positive lead I2, of platinum or the like, communicates with the bottom of the positive leg or pole portion in recessses I0. Similarly, a negative lead I3 communicates with the bottom of the negative leg or pole piece in the recesses II. Leads I2 and I3 may be inserted in casing 7 by being heated and passed through the wall of the casing i. The wall of the casing cools around the leads I2 and I3 and seals to form a fluid-tight joint. Electrolyte I4, consisting of cadmium sulphate (CdSOt) is placed in a cavity 8 before cap 9 is secured in position and passes vdown through perforations in corks I5 which are located in the positive and negative pole portions In and II. Electrolyte I I may be saturated or unsaturated. Corks I5 are surrounded at their bottom and sides with a layer of cloth I6, conveniently of linen. The cork and cloth in recesses ID are shown in vertical cross section while the cork and cloth in recess II are shown in side elevation. In the positive recess Ii) is a layer of mercurous sulphate paste I'I (HgzSO4). Surrounding the upper end of positive lead I2 is a body of pure mercury I8.

In negative recess II is a layer I I of cadmium sulphate and, surrounding the upper end of negative lead I3, is a bead I9 of cadmium amalgam.

Also secured to case I is a lower back 2c supporting pole pieces 2| and 22, which pass through it and each of which is attached at one end to the lower end of positive lead I2 or negative lead I3. Terminals 23 and 24 are secured on the rear of lower back 20 and have connection with pole pieces 2| and 22 and project beneath the lower back 20 so as to afford connection for wires to a potentiometer or the like.

This primary cell has a positive electrode consisting of the active material formed by the layer of mercurous sulphate paste II, and the body of mercury I8, the lead I2, the pole piece 2I, and the terminal 23. The negative electrode consists of the active material comprising the bead I9 of cadmium amalgam, the lead I3, the pole piece 22, and the terminal 24.

Figs. 3 and 4 show a plurality of cells, similar to the cell just described, grouped around a common reservoir. In this modification, the container II has a cavity 88 in it in which is located a body I4I of electrolyte of cadmium sulphate. As is best seen in Fig. 4, the bottom of cavity 88 has a plurality of smaller recesses IIlI, I63, I and I0! communicating with it. Also communieating with cavity 88 are a second plurality of recesses H0, H2, H4 and H6. The odd numbered recesses form positive legs while the even numbered recesses form negative legs. For example, cavity IOI contains a perforated cork I50 surrounded by a cloth layer I60 beneath which is a layer of mercurous sulphate I10 and a pool of mercury I80 engaging with the end of positive lead I20.

A base 50 is secured to container 11 as by a screw 5| and has a flanged edge or rim 52 forming a cavity 53 in the bottom thereof in which the electrodes are located.

The outer or free end of lead I20, for example, is secured to a terminal wire forming a portion of a terminal having a central opening 63 formed in a body of insulation.

The recess II2, which forms one of the negative legs or pole pieces, contains a cork I50 surrounded by a cloth I00 and a layer of cadmium sulphate MI above a body of cadmium amalgam I90 which engages with the inner end of negative lead I30.

Negative lead I30 is secured at its outer end to a terminal wire 00 which forms part of a terminal having an opening 62 formed in a body 64 of insulation.

The odd numbered, positive terminals 65, 01, 69 and II may be clifierently colored or otherwise distinguished from the even numbered, negative terminals 64, 66, 68 and I2.

This plurality of primary cells has, for example, positive electrodes consisting of the active material comprising a layer of mercurous sulphate I and the pool of mercury I80, the lead I20, the terminal wire BI, and the terminal to which wire BI is attached. The negative electrodes comprise, for example, the body of cadmium amalgam I90, the lead I30, the terminal wire 60, and the terminal to which the wire 60 is connected.

In order to maintain the positive and negative pole portions at as nearly the same temperature as possible, the casing 17 is surrounded with a cover I0 of inverted cup-shape of metal of good thermal conductivity, such as aluminum or copper. Any positive recess may be connected with any negative recess to form a standard cell by connecting an odd numbered terminal with an even numbered terminal. Thus, this device provides a plurality of standard cells maintained at substantially the same temperature and giving an extremely accurate reference of voltage.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of the invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the 4 apparatus disclosed without departing from the spirit of the invention as set forth in the appended claims, and that in some cases certain features of the invention may sometimes be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is as follows:

1. A group of standard primary cells including, a closed hollow body of a plastic selected from the class consisting of polystyrene, polyethylene or polytetrafluoroethylene and having a cavity therein and a plurality of smaller separate recesses each communicating individually with said cavity, an electrolyte of a solution of cadmium sulphate in said cavity and in said recesses, a plurality of bodies of mercurous sulphate each located in an alternate one of said recesses to form positive pole portions, positive electrodes each communicating at one end with one of said bodies of mercurous sulphate, and a plurality of negative electrodes each communicating at one end with the electrolyte in one of the recesses intermediate said alternate recesses containing mercurous sulphate.

2. A group of standard primary cells including, a closed hollow body having a cavity communicating with a plurality of separate recesses therein, said body being composed of a plastic selected from the class consisting of polystyrene, polyethylene or polytetrafiuoroethylene, chemically active voltage producing materials in said recesses in the cavity in said body, and a cover of inverted cup shape surrounding the hollow and the recesses in said body and composed of metallic material of good heat-conductivity to equalize the temperature in each of said recesses.

CLARENCE A. DYER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 439,737 Weston Nov. 4, 1890 494,827 Weston Apr. 4, 1893 2,153,152 Mucher Apr. 4, 1939 2,176,427 Kershaw Oct. 17, 1939 2,349,763 Setzer May 23, 1944 2,400,094 Benning May 14, 1946 FOREIGN PATENTS Number Country Date 217,685 Germany Feb. 20, 1909 OTHER REFERENCES Richards, Carnegie Inst. Publ. 118 (1909) pages 15, 16. 

2. A GROUP OF STANDARD PRIMARY CELLS INCLUDING, A CLOSED HOLLOW BODY HAVING A CAVITY COMMUNICATING WITH A PLURALITY OF SEPARATE RECESSES THEREIN, SAID BODY BEING COMPOSED OF A PLASTIC SELECTED FROM THE CLASS CONSISTING OF POLYSTYRENE, POLYETHYLENE OR POLYTETRAFLUOROETHYLENE, CHEMICALL ACTIVE VOLTAGE PRODUCING MATERIALS IN SAID 